Parachute systems will typically includes a main parachute and a reserve parachute as a backup in the event of main parachute failure. The main parachute assembly will include a quick release mechanism so that the main canopy can be released from the body harness warn by the parachutist or jumper in case of main parachute failure or malfunction. It is usually necessary that the main parachute be completely released or disconnected from the body harness before the reserve parachute is deployed in order to avoid entanglement, and fatal results. Quick release devices are described in U.S. Pat. No. 4,337,913 to Booth and U.S. Pat. No. 4,428,102 to Brownell, by way of example.
In addition to the main parachute releases, Reserve Static Line (RSL) Systems have been used in sport parachuting for many years. Their purpose is to open the reserve parachute container immediately upon a "cutaway" or release of the main parachute, in the event of its malfunction. The RSL typically includes a cord attached at one end to one main parachute riser, and at the other end to the ripcord of the reserve parachute.
An RSL functions well if both main parachute risers release simultaneously. However, if only the riser to which the RSL is connected releases, and the other main parachute riser remains attached to the jumper's harness, the RSL will deploy the reserve parachute which can open into the partially connected main parachute, possibly resulting in entanglement, thus leading to possible injury or death. Accordingly, it is vital that the main parachute be fully released to protect the jumper from possible disaster.
Attempts have been made to overcome this shortcoming. By way of example, one approaches tried in the past includes the use of two RSL's, one from each main riser, connected to two reserve ripcord pins. However, both main risers must be jettisoned before the reserve will be deployed. Another approach involves the use of a cross connector between both main risers that will not allow either riser to go very far without the other. Although such approaches will work, they are awkward to assemble and both create new malfunction possibilities just as hazardous the problem they are trying to prevent.